I followed the Arch Wiki on Nvidia (using the nvidia-580xx-dkms driver), Wayland, KDE and this guide Plasma/Wayland/Nvidia - KDE Community Wiki , but “qdbus6 org.kde.KWin /KWin supportInformation” still shows my Intel GPU under Compositing.
What am i missing?
By chance i noticed today that, for some reason (perhaps the update of the linux-firmware?), the Nvidia GPU was finally active for once. Unfortunately, this did not last long, because after a reboot, it reverted back to the Intel GPU without any further changes.
Now I know at least that it is possible and that all the requirements are actually met. Still puzzled why the Intel GPU is preferred over the Nvidia one.
Because as hybrid Graphics was “basically invented (but maybe I’m wrong here)” for Notebooks it is for battery saving reasons i would guess, or at least for that reason the less powerful / less powerhungry is usually prioritized until you explicitly demand the more powerful for a specific application.
Or is in your case the Intel GPU the more powerful and it should be the other way around?
KWIN_DRM_DEVICES set at /etc/environment Environment Variables · Wiki · Plasma / KWin · GitLab maybe.
I have used that to prioritize Nvidia, last time very very early Plasma 6 but not anymore, colon-separated the first was the prioritized one if I remember correctly.
But if it is an Intel iGPU and you don’t want to use it at all, I would rather suggest to deactivate in bios and set it to dedicated GPU (Nvidia) only there.
Thank you for taking time to answer. I see, that makes sense. So that is probably why the weaker Intel GPU is (mostly) choosen.
Regarding your link, i found something similar in the Arch Wiki (KDE):
For direct control over KWin’s GPU selection, i created ~/.config/plasma-workspace/env/gpu.sh and tried with
#!/bin/bash
export KWIN_DRM_DEVICES=/dev/dri/card1:/dev/dri/card0
and
#!/bin/bash
export KWIN_DRM_DEVICES=/dev/dri/card0:/dev/dri/card1
Unfortunately, the system would boot into a black screen on both attenpts (before display manager even starts).
I think i just leave it with the system choosing the right GPU.
In that case don 't forget to install and enable switcheroo-control (assuming you are on Arch) otherwise the easier to manage “Run using dedicated graphics card” option will not be there.
.
Thank you, but this is for starting applications with the Nvidia GPU, right? i think i will just stay with prime-run.
Anyway, having an option in KDE’s system settings to select KWin’s GPU backend would be nice to have.
Yes, the “Discrete/dedicated” GPU should in this case be Nvidia.
But I use prime-run too, for example for the steam game launcher command line
prime-run %command% instead of the long one the archwiki suggests (works for me 
).
